P57 Fontan-associated liver disease lesion review

<h3>Introduction</h3> Fontan-associated liver disease (FALD) is an increasingly recognised complication amongst adults with a total cavopulmonary circulation. The prevalence of liver lesions is reported to be up to 48%. Whilst frequently benign regenerative nodules, there is a reported increased risk of hepatocellular carcinoma (HCC). Due to haemodynamic changes these lesions are often difficult to characterise. As a regional referral centre for Fontan patients in the UK, we reviewed liver lesion outcomes in our population over the last decade. <h3>Method</h3> Description of imaging, demographics, blood results, cardiac metrics, and histological profiles from a regional Fontan database, using electronic patient records. Non-parametric data was compared between patients with and without lesions using a Mann Whitney U test. <h3>Results</h3> Records between 2014 – 2024 were reviewed, 71/104 patients had at least one liver imaging result; 18/71 (28%) had reported liver lesions (5/18, 28% single, 13/18, 72% multiple lesions). All patients had ultrasound scans. 8/18 (39%) had cross-sectional imaging (7 MRI – one without contrast; 1 CT). 6/7 had arterial enhancement on cross-sectional imaging with contrast. Reported lesion size varied &lt;10–63mm. Alpha feto protein ranged from 2–7kU/L. 14/18 were given a likely diagnosis, on the imaging report or with histology. 9 Nodular regenerative hyperplasia/focal nodular hyperplasia, 2 haemangiomas, 1 cyst, 1 bile duct hamaratomatosis and 1 ‘remodeling changes’. Three patients underwent lesional biopsies (all had multiple lesions) due to LiRAD scores of 4/5. One patient underwent microwave ablation at the time of biopsy due to interim growth on imaging. All histology was benign, and consistent with regenerative changes. No patients have been found to have HCC. There was no significant difference between years post Fontan procedure, Fontan pressure or liver stiffness measurement in developing liver lesions, see table 1. <h3>Conclusion</h3> Liver lesions were present in over a quarter of our cohort. Whilst some had LiRAD scores which would be diagnostic of HCC in chronic liver disease, no malignant lesions were identified with all suspicious lesions ultimately found to be benign. Our cohort did not demonstrate a link between duration of Fontan procedure, Fontan pressure or liver stiffness measurement and the development of lesions, which differs from the recent European position paper on FALD.¹ Better understanding of the characteristics of liver lesions encountered in FALD and a tailored surveillance pathway should be established to ensure appropriate investigation, diagnosis, management and discussions with patients. Doing so could prevent unnecessary invasive procedures and reduce patient anxiety. <h3>Reference</h3> Téllez L, Payancé A, Tjwa E, Del Cerro MJ, <i>et al</i>. EASL-ERN position paper on liver involvement in patients with Fontan-type circulation. <i>J Hepatol</i>. 2023 Nov;<b>79</b>(5):1270–1301. doi: 10.1016/j.jhep.2023.07.013. PMID: 37863545.